This invention relates to a sprag retainer wherein assembly is simplified over prior art sprag retainers.
Sprag retainers are utilized to maintain the position of sprag members which selectively transmit rotation between an inner race and an outer race in one-way sprag clutches. The sprag members must be properly positioned for proper functioning of a clutch. At the same time, it is desirable to reduce the complexity of sprag retainer assembly.
One prior art sprag retainer has annular axial end members with cross members connecting the two axial end members. Outer peripheral surfaces of each axial end member and at least a central portion of the cross members all extend radially outwardly for the same distance. All three surfaces are urged into contact with an inner peripheral surface of an outer race. The prior art sprag retainer uses the three contact areas to securely retain the sprag retainer relative to the outer race.
Deficiencies exist with such prior art sprag retainers. First, although it is desirable to maintain some contact between the sprag retainer and the outer race in some applications, it is also desirable to minimize the area of that contact. Sprag clutches are one-way, and transmit rotation between the inner and outer race when the rotational speed of a first race exceeds the rotational speed of a second race. On the other hand, if the rotational speed of the second race exceeds that of the first race, the sprag clutch will not transmit rotation. In this "overrunning" condition, the outer race typically rotates with the sprag retainer. When rotation, or torque, is transmitted the outer race deflects radially outwardly, out of contact with the retainer. To assist in this function, it is desirable that the contact area between the sprag retainer and the outer race be minimized. The above-discussed sprag retainer has an undesirably high amount of contact area.
Further, the prior art sprag retainer is somewhat difficult to assemble, in that the three axially spaced contact surfaces must each be individually forced into the outer race when assembling the sprag clutch. This may sometimes be difficult.